gistfile1.m

- (void)updateFromJson:(NSDictionary *)json
{
	NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
	[formatter setDateFormat:@"yyyy-MM-dd'T'HHmmssZ"];
	NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"_(\\w)" options:0 error:NULL];
	[json enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
		if (obj == [NSNull null]) return;
		if ([key isEqual:@"id"]) return;
		NSString *_key = [key stringByReplacingOccurrencesOfString:@"class" withString:@"group"];
		NSMutableString *newKey = [NSMutableString string];
		__block NSInteger loc = 0;
		__block NSInteger shorten = 0;
		[regex enumerateMatchesInString:_key options:0 range:NSMakeRange(0, _key.length) usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
			NSRange r = [result rangeAtIndex:1];
			[newKey appendString:[_key substringWithRange:NSMakeRange(loc, r.location - 1 - loc)]];
			[newKey appendString:[[_key substringWithRange:r] uppercaseString]];
			loc = r.location + 1;
			shorten++;
		}];
		[newKey appendString:[_key substringWithRange:NSMakeRange(loc, _key.length - loc)]];
		if ([newKey hasSuffix:@"At"]) {
			obj = [formatter dateFromString:[obj stringByReplacingOccurrencesOfString:@":" withString:@""]];
		}
		if (![[self valueForKey:newKey] isEqual:obj]) {
			[self setValue:obj forKey:newKey];
		}
	}];
}